xref: /aosp_15_r20/external/cronet/base/files/file_path.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1*6777b538SAndroid Build Coastguard Worker // Copyright 2012 The Chromium Authors
2*6777b538SAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be
3*6777b538SAndroid Build Coastguard Worker // found in the LICENSE file.
4*6777b538SAndroid Build Coastguard Worker 
5*6777b538SAndroid Build Coastguard Worker // FilePath is a container for pathnames stored in a platform's native string
6*6777b538SAndroid Build Coastguard Worker // type, providing containers for manipulation in according with the
7*6777b538SAndroid Build Coastguard Worker // platform's conventions for pathnames.  It supports the following path
8*6777b538SAndroid Build Coastguard Worker // types:
9*6777b538SAndroid Build Coastguard Worker //
10*6777b538SAndroid Build Coastguard Worker //                   POSIX            Windows
11*6777b538SAndroid Build Coastguard Worker //                   ---------------  ----------------------------------
12*6777b538SAndroid Build Coastguard Worker // Fundamental type  char[]           wchar_t[]
13*6777b538SAndroid Build Coastguard Worker // Encoding          unspecified*     UTF-16
14*6777b538SAndroid Build Coastguard Worker // Separator         /                \, tolerant of /
15*6777b538SAndroid Build Coastguard Worker // Drive letters     no               case-insensitive A-Z followed by :
16*6777b538SAndroid Build Coastguard Worker // Alternate root    // (surprise!)   \\ (2 Separators), for UNC paths
17*6777b538SAndroid Build Coastguard Worker //
18*6777b538SAndroid Build Coastguard Worker // * The encoding need not be specified on POSIX systems, although some
19*6777b538SAndroid Build Coastguard Worker //   POSIX-compliant systems do specify an encoding.  Mac OS X uses UTF-8.
20*6777b538SAndroid Build Coastguard Worker //   Chrome OS also uses UTF-8.
21*6777b538SAndroid Build Coastguard Worker //   Linux does not specify an encoding, but in practice, the locale's
22*6777b538SAndroid Build Coastguard Worker //   character set may be used.
23*6777b538SAndroid Build Coastguard Worker //
24*6777b538SAndroid Build Coastguard Worker // For more arcane bits of path trivia, see below.
25*6777b538SAndroid Build Coastguard Worker //
26*6777b538SAndroid Build Coastguard Worker // FilePath objects are intended to be used anywhere paths are.  An
27*6777b538SAndroid Build Coastguard Worker // application may pass FilePath objects around internally, masking the
28*6777b538SAndroid Build Coastguard Worker // underlying differences between systems, only differing in implementation
29*6777b538SAndroid Build Coastguard Worker // where interfacing directly with the system.  For example, a single
30*6777b538SAndroid Build Coastguard Worker // OpenFile(const FilePath &) function may be made available, allowing all
31*6777b538SAndroid Build Coastguard Worker // callers to operate without regard to the underlying implementation.  On
32*6777b538SAndroid Build Coastguard Worker // POSIX-like platforms, OpenFile might wrap fopen, and on Windows, it might
33*6777b538SAndroid Build Coastguard Worker // wrap _wfopen_s, perhaps both by calling file_path.value().c_str().  This
34*6777b538SAndroid Build Coastguard Worker // allows each platform to pass pathnames around without requiring conversions
35*6777b538SAndroid Build Coastguard Worker // between encodings, which has an impact on performance, but more imporantly,
36*6777b538SAndroid Build Coastguard Worker // has an impact on correctness on platforms that do not have well-defined
37*6777b538SAndroid Build Coastguard Worker // encodings for pathnames.
38*6777b538SAndroid Build Coastguard Worker //
39*6777b538SAndroid Build Coastguard Worker // Several methods are available to perform common operations on a FilePath
40*6777b538SAndroid Build Coastguard Worker // object, such as determining the parent directory (DirName), isolating the
41*6777b538SAndroid Build Coastguard Worker // final path component (BaseName), and appending a relative pathname string
42*6777b538SAndroid Build Coastguard Worker // to an existing FilePath object (Append).  These methods are highly
43*6777b538SAndroid Build Coastguard Worker // recommended over attempting to split and concatenate strings directly.
44*6777b538SAndroid Build Coastguard Worker // These methods are based purely on string manipulation and knowledge of
45*6777b538SAndroid Build Coastguard Worker // platform-specific pathname conventions, and do not consult the filesystem
46*6777b538SAndroid Build Coastguard Worker // at all, making them safe to use without fear of blocking on I/O operations.
47*6777b538SAndroid Build Coastguard Worker // These methods do not function as mutators but instead return distinct
48*6777b538SAndroid Build Coastguard Worker // instances of FilePath objects, and are therefore safe to use on const
49*6777b538SAndroid Build Coastguard Worker // objects.  The objects themselves are safe to share between threads.
50*6777b538SAndroid Build Coastguard Worker //
51*6777b538SAndroid Build Coastguard Worker // To aid in initialization of FilePath objects from string literals, a
52*6777b538SAndroid Build Coastguard Worker // FILE_PATH_LITERAL macro is provided, which accounts for the difference
53*6777b538SAndroid Build Coastguard Worker // between char[]-based pathnames on POSIX systems and wchar_t[]-based
54*6777b538SAndroid Build Coastguard Worker // pathnames on Windows.
55*6777b538SAndroid Build Coastguard Worker //
56*6777b538SAndroid Build Coastguard Worker // As a precaution against premature truncation, paths can't contain NULs.
57*6777b538SAndroid Build Coastguard Worker //
58*6777b538SAndroid Build Coastguard Worker // Because a FilePath object should not be instantiated at the global scope,
59*6777b538SAndroid Build Coastguard Worker // instead, use a FilePath::CharType[] and initialize it with
60*6777b538SAndroid Build Coastguard Worker // FILE_PATH_LITERAL.  At runtime, a FilePath object can be created from the
61*6777b538SAndroid Build Coastguard Worker // character array.  Example:
62*6777b538SAndroid Build Coastguard Worker //
63*6777b538SAndroid Build Coastguard Worker // | const FilePath::CharType kLogFileName[] = FILE_PATH_LITERAL("log.txt");
64*6777b538SAndroid Build Coastguard Worker // |
65*6777b538SAndroid Build Coastguard Worker // | void Function() {
66*6777b538SAndroid Build Coastguard Worker // |   FilePath log_file_path(kLogFileName);
67*6777b538SAndroid Build Coastguard Worker // |   [...]
68*6777b538SAndroid Build Coastguard Worker // | }
69*6777b538SAndroid Build Coastguard Worker //
70*6777b538SAndroid Build Coastguard Worker // WARNING: FilePaths should ALWAYS be displayed with LTR directionality, even
71*6777b538SAndroid Build Coastguard Worker // when the UI language is RTL. This means you always need to pass filepaths
72*6777b538SAndroid Build Coastguard Worker // through base::i18n::WrapPathWithLTRFormatting() before displaying it in the
73*6777b538SAndroid Build Coastguard Worker // RTL UI.
74*6777b538SAndroid Build Coastguard Worker //
75*6777b538SAndroid Build Coastguard Worker // This is a very common source of bugs, please try to keep this in mind.
76*6777b538SAndroid Build Coastguard Worker //
77*6777b538SAndroid Build Coastguard Worker // ARCANE BITS OF PATH TRIVIA
78*6777b538SAndroid Build Coastguard Worker //
79*6777b538SAndroid Build Coastguard Worker //  - A double leading slash is actually part of the POSIX standard.  Systems
80*6777b538SAndroid Build Coastguard Worker //    are allowed to treat // as an alternate root, as Windows does for UNC
81*6777b538SAndroid Build Coastguard Worker //    (network share) paths.  Most POSIX systems don't do anything special
82*6777b538SAndroid Build Coastguard Worker //    with two leading slashes, but FilePath handles this case properly
83*6777b538SAndroid Build Coastguard Worker //    in case it ever comes across such a system.  FilePath needs this support
84*6777b538SAndroid Build Coastguard Worker //    for Windows UNC paths, anyway.
85*6777b538SAndroid Build Coastguard Worker //    References:
86*6777b538SAndroid Build Coastguard Worker //    The Open Group Base Specifications Issue 7, sections 3.267 ("Pathname")
87*6777b538SAndroid Build Coastguard Worker //    and 4.12 ("Pathname Resolution"), available at:
88*6777b538SAndroid Build Coastguard Worker //    http://www.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_267
89*6777b538SAndroid Build Coastguard Worker //    http://www.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_12
90*6777b538SAndroid Build Coastguard Worker //
91*6777b538SAndroid Build Coastguard Worker //  - Windows treats c:\\ the same way it treats \\.  This was intended to
92*6777b538SAndroid Build Coastguard Worker //    allow older applications that require drive letters to support UNC paths
93*6777b538SAndroid Build Coastguard Worker //    like \\server\share\path, by permitting c:\\server\share\path as an
94*6777b538SAndroid Build Coastguard Worker //    equivalent.  Since the OS treats these paths specially, FilePath needs
95*6777b538SAndroid Build Coastguard Worker //    to do the same.  Since Windows can use either / or \ as the separator,
96*6777b538SAndroid Build Coastguard Worker //    FilePath treats c://, c:\\, //, and \\ all equivalently.
97*6777b538SAndroid Build Coastguard Worker //    Reference:
98*6777b538SAndroid Build Coastguard Worker //    The Old New Thing, "Why is a drive letter permitted in front of UNC
99*6777b538SAndroid Build Coastguard Worker //    paths (sometimes)?", available at:
100*6777b538SAndroid Build Coastguard Worker //    http://blogs.msdn.com/oldnewthing/archive/2005/11/22/495740.aspx
101*6777b538SAndroid Build Coastguard Worker 
102*6777b538SAndroid Build Coastguard Worker #ifndef BASE_FILES_FILE_PATH_H_
103*6777b538SAndroid Build Coastguard Worker #define BASE_FILES_FILE_PATH_H_
104*6777b538SAndroid Build Coastguard Worker 
105*6777b538SAndroid Build Coastguard Worker #include <cstddef>
106*6777b538SAndroid Build Coastguard Worker #include <iosfwd>
107*6777b538SAndroid Build Coastguard Worker #include <string>
108*6777b538SAndroid Build Coastguard Worker #include <string_view>
109*6777b538SAndroid Build Coastguard Worker #include <vector>
110*6777b538SAndroid Build Coastguard Worker 
111*6777b538SAndroid Build Coastguard Worker #include "base/base_export.h"
112*6777b538SAndroid Build Coastguard Worker #include "base/strings/string_piece.h"
113*6777b538SAndroid Build Coastguard Worker #include "base/trace_event/base_tracing_forward.h"
114*6777b538SAndroid Build Coastguard Worker #include "build/build_config.h"
115*6777b538SAndroid Build Coastguard Worker 
116*6777b538SAndroid Build Coastguard Worker // Windows-style drive letter support and pathname separator characters can be
117*6777b538SAndroid Build Coastguard Worker // enabled and disabled independently, to aid testing.  These #defines are
118*6777b538SAndroid Build Coastguard Worker // here so that the same setting can be used in both the implementation and
119*6777b538SAndroid Build Coastguard Worker // in the unit test.
120*6777b538SAndroid Build Coastguard Worker #if BUILDFLAG(IS_WIN)
121*6777b538SAndroid Build Coastguard Worker #define FILE_PATH_USES_DRIVE_LETTERS
122*6777b538SAndroid Build Coastguard Worker #define FILE_PATH_USES_WIN_SEPARATORS
123*6777b538SAndroid Build Coastguard Worker #endif  // BUILDFLAG(IS_WIN)
124*6777b538SAndroid Build Coastguard Worker 
125*6777b538SAndroid Build Coastguard Worker // To print path names portably use PRFilePath (based on PRIuS and friends from
126*6777b538SAndroid Build Coastguard Worker // C99 and format_macros.h) like this:
127*6777b538SAndroid Build Coastguard Worker // base::StringPrintf("Path is %" PRFilePath ".\n", path.value().c_str());
128*6777b538SAndroid Build Coastguard Worker #if BUILDFLAG(IS_WIN)
129*6777b538SAndroid Build Coastguard Worker #define PRFilePath "ls"
130*6777b538SAndroid Build Coastguard Worker #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
131*6777b538SAndroid Build Coastguard Worker #define PRFilePath "s"
132*6777b538SAndroid Build Coastguard Worker #endif  // BUILDFLAG(IS_WIN)
133*6777b538SAndroid Build Coastguard Worker 
134*6777b538SAndroid Build Coastguard Worker // Macros for string literal initialization of FilePath::CharType[].
135*6777b538SAndroid Build Coastguard Worker #if BUILDFLAG(IS_WIN)
136*6777b538SAndroid Build Coastguard Worker 
137*6777b538SAndroid Build Coastguard Worker // The `FILE_PATH_LITERAL_INTERNAL` indirection allows `FILE_PATH_LITERAL` to
138*6777b538SAndroid Build Coastguard Worker // work correctly with macro parameters, for example
139*6777b538SAndroid Build Coastguard Worker // `FILE_PATH_LITERAL(TEST_FILE)` where `TEST_FILE` is a macro #defined as
140*6777b538SAndroid Build Coastguard Worker // "TestFile".
141*6777b538SAndroid Build Coastguard Worker #define FILE_PATH_LITERAL_INTERNAL(x) L##x
142*6777b538SAndroid Build Coastguard Worker #define FILE_PATH_LITERAL(x) FILE_PATH_LITERAL_INTERNAL(x)
143*6777b538SAndroid Build Coastguard Worker 
144*6777b538SAndroid Build Coastguard Worker #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
145*6777b538SAndroid Build Coastguard Worker #define FILE_PATH_LITERAL(x) x
146*6777b538SAndroid Build Coastguard Worker #endif  // BUILDFLAG(IS_WIN)
147*6777b538SAndroid Build Coastguard Worker 
148*6777b538SAndroid Build Coastguard Worker namespace base {
149*6777b538SAndroid Build Coastguard Worker 
150*6777b538SAndroid Build Coastguard Worker class SafeBaseName;
151*6777b538SAndroid Build Coastguard Worker class Pickle;
152*6777b538SAndroid Build Coastguard Worker class PickleIterator;
153*6777b538SAndroid Build Coastguard Worker 
154*6777b538SAndroid Build Coastguard Worker // An abstraction to isolate users from the differences between native
155*6777b538SAndroid Build Coastguard Worker // pathnames on different platforms.
156*6777b538SAndroid Build Coastguard Worker class BASE_EXPORT FilePath {
157*6777b538SAndroid Build Coastguard Worker  public:
158*6777b538SAndroid Build Coastguard Worker #if BUILDFLAG(IS_WIN)
159*6777b538SAndroid Build Coastguard Worker   // On Windows, for Unicode-aware applications, native pathnames are wchar_t
160*6777b538SAndroid Build Coastguard Worker   // arrays encoded in UTF-16.
161*6777b538SAndroid Build Coastguard Worker   typedef std::wstring StringType;
162*6777b538SAndroid Build Coastguard Worker #elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
163*6777b538SAndroid Build Coastguard Worker   // On most platforms, native pathnames are char arrays, and the encoding
164*6777b538SAndroid Build Coastguard Worker   // may or may not be specified.  On Mac OS X, native pathnames are encoded
165*6777b538SAndroid Build Coastguard Worker   // in UTF-8.
166*6777b538SAndroid Build Coastguard Worker   typedef std::string StringType;
167*6777b538SAndroid Build Coastguard Worker #endif  // BUILDFLAG(IS_WIN)
168*6777b538SAndroid Build Coastguard Worker 
169*6777b538SAndroid Build Coastguard Worker   typedef StringType::value_type CharType;
170*6777b538SAndroid Build Coastguard Worker   typedef std::basic_string_view<CharType> StringPieceType;
171*6777b538SAndroid Build Coastguard Worker 
172*6777b538SAndroid Build Coastguard Worker   // Null-terminated array of separators used to separate components in paths.
173*6777b538SAndroid Build Coastguard Worker   // Each character in this array is a valid separator, but kSeparators[0] is
174*6777b538SAndroid Build Coastguard Worker   // treated as the canonical separator and is used when composing pathnames.
175*6777b538SAndroid Build Coastguard Worker   static constexpr CharType kSeparators[] =
176*6777b538SAndroid Build Coastguard Worker #if defined(FILE_PATH_USES_WIN_SEPARATORS)
177*6777b538SAndroid Build Coastguard Worker       FILE_PATH_LITERAL("\\/");
178*6777b538SAndroid Build Coastguard Worker #else   // FILE_PATH_USES_WIN_SEPARATORS
179*6777b538SAndroid Build Coastguard Worker       FILE_PATH_LITERAL("/");
180*6777b538SAndroid Build Coastguard Worker #endif  // FILE_PATH_USES_WIN_SEPARATORS
181*6777b538SAndroid Build Coastguard Worker 
182*6777b538SAndroid Build Coastguard Worker   // std::size(kSeparators), i.e., the number of separators in kSeparators plus
183*6777b538SAndroid Build Coastguard Worker   // one (the null terminator at the end of kSeparators).
184*6777b538SAndroid Build Coastguard Worker   static constexpr size_t kSeparatorsLength = std::size(kSeparators);
185*6777b538SAndroid Build Coastguard Worker 
186*6777b538SAndroid Build Coastguard Worker   // The special path component meaning "this directory."
187*6777b538SAndroid Build Coastguard Worker   static constexpr CharType kCurrentDirectory[] = FILE_PATH_LITERAL(".");
188*6777b538SAndroid Build Coastguard Worker 
189*6777b538SAndroid Build Coastguard Worker   // The special path component meaning "the parent directory."
190*6777b538SAndroid Build Coastguard Worker   static constexpr CharType kParentDirectory[] = FILE_PATH_LITERAL("..");
191*6777b538SAndroid Build Coastguard Worker 
192*6777b538SAndroid Build Coastguard Worker   // The character used to identify a file extension.
193*6777b538SAndroid Build Coastguard Worker   static constexpr CharType kExtensionSeparator = FILE_PATH_LITERAL('.');
194*6777b538SAndroid Build Coastguard Worker 
195*6777b538SAndroid Build Coastguard Worker   FilePath();
196*6777b538SAndroid Build Coastguard Worker   FilePath(const FilePath& that);
197*6777b538SAndroid Build Coastguard Worker   explicit FilePath(StringPieceType path);
198*6777b538SAndroid Build Coastguard Worker   ~FilePath();
199*6777b538SAndroid Build Coastguard Worker   FilePath& operator=(const FilePath& that);
200*6777b538SAndroid Build Coastguard Worker 
201*6777b538SAndroid Build Coastguard Worker   // Constructs FilePath with the contents of |that|, which is left in valid but
202*6777b538SAndroid Build Coastguard Worker   // unspecified state.
203*6777b538SAndroid Build Coastguard Worker   FilePath(FilePath&& that) noexcept;
204*6777b538SAndroid Build Coastguard Worker   // Replaces the contents with those of |that|, which is left in valid but
205*6777b538SAndroid Build Coastguard Worker   // unspecified state.
206*6777b538SAndroid Build Coastguard Worker   FilePath& operator=(FilePath&& that) noexcept;
207*6777b538SAndroid Build Coastguard Worker 
208*6777b538SAndroid Build Coastguard Worker   bool operator==(const FilePath& that) const;
209*6777b538SAndroid Build Coastguard Worker 
210*6777b538SAndroid Build Coastguard Worker   bool operator!=(const FilePath& that) const;
211*6777b538SAndroid Build Coastguard Worker 
212*6777b538SAndroid Build Coastguard Worker   // Required for some STL containers and operations
213*6777b538SAndroid Build Coastguard Worker   bool operator<(const FilePath& that) const {
214*6777b538SAndroid Build Coastguard Worker     return path_ < that.path_;
215*6777b538SAndroid Build Coastguard Worker   }
216*6777b538SAndroid Build Coastguard Worker 
value()217*6777b538SAndroid Build Coastguard Worker   const StringType& value() const { return path_; }
218*6777b538SAndroid Build Coastguard Worker 
empty()219*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] bool empty() const { return path_.empty(); }
220*6777b538SAndroid Build Coastguard Worker 
clear()221*6777b538SAndroid Build Coastguard Worker   void clear() { path_.clear(); }
222*6777b538SAndroid Build Coastguard Worker 
223*6777b538SAndroid Build Coastguard Worker   // Returns true if |character| is in kSeparators.
224*6777b538SAndroid Build Coastguard Worker   static bool IsSeparator(CharType character);
225*6777b538SAndroid Build Coastguard Worker 
226*6777b538SAndroid Build Coastguard Worker   // Returns a vector of all of the components of the provided path. It is
227*6777b538SAndroid Build Coastguard Worker   // equivalent to calling DirName().value() on the path's root component,
228*6777b538SAndroid Build Coastguard Worker   // and BaseName().value() on each child component.
229*6777b538SAndroid Build Coastguard Worker   //
230*6777b538SAndroid Build Coastguard Worker   // To make sure this is lossless so we can differentiate absolute and
231*6777b538SAndroid Build Coastguard Worker   // relative paths, the root slash will be included even though no other
232*6777b538SAndroid Build Coastguard Worker   // slashes will be. The precise behavior is:
233*6777b538SAndroid Build Coastguard Worker   //
234*6777b538SAndroid Build Coastguard Worker   // Posix:  "/foo/bar"  ->  [ "/", "foo", "bar" ]
235*6777b538SAndroid Build Coastguard Worker   // Windows:  "C:\foo\bar"  ->  [ "C:", "\\", "foo", "bar" ]
236*6777b538SAndroid Build Coastguard Worker   std::vector<FilePath::StringType> GetComponents() const;
237*6777b538SAndroid Build Coastguard Worker 
238*6777b538SAndroid Build Coastguard Worker   // Returns true if this FilePath is a parent or ancestor of the |child|.
239*6777b538SAndroid Build Coastguard Worker   // Absolute and relative paths are accepted i.e. /foo is a parent to /foo/bar,
240*6777b538SAndroid Build Coastguard Worker   // and foo is a parent to foo/bar. Any ancestor is considered a parent i.e. /a
241*6777b538SAndroid Build Coastguard Worker   // is a parent to both /a/b and /a/b/c.  Does not convert paths to absolute,
242*6777b538SAndroid Build Coastguard Worker   // follow symlinks or directory navigation (e.g. ".."). A path is *NOT* its
243*6777b538SAndroid Build Coastguard Worker   // own parent.
244*6777b538SAndroid Build Coastguard Worker   bool IsParent(const FilePath& child) const;
245*6777b538SAndroid Build Coastguard Worker 
246*6777b538SAndroid Build Coastguard Worker   // If IsParent(child) holds, appends to path (if non-NULL) the
247*6777b538SAndroid Build Coastguard Worker   // relative path to child and returns true.  For example, if parent
248*6777b538SAndroid Build Coastguard Worker   // holds "/Users/johndoe/Library/Application Support", child holds
249*6777b538SAndroid Build Coastguard Worker   // "/Users/johndoe/Library/Application Support/Google/Chrome/Default", and
250*6777b538SAndroid Build Coastguard Worker   // *path holds "/Users/johndoe/Library/Caches", then after
251*6777b538SAndroid Build Coastguard Worker   // parent.AppendRelativePath(child, path) is called *path will hold
252*6777b538SAndroid Build Coastguard Worker   // "/Users/johndoe/Library/Caches/Google/Chrome/Default".  Otherwise,
253*6777b538SAndroid Build Coastguard Worker   // returns false.
254*6777b538SAndroid Build Coastguard Worker   bool AppendRelativePath(const FilePath& child, FilePath* path) const;
255*6777b538SAndroid Build Coastguard Worker 
256*6777b538SAndroid Build Coastguard Worker   // Returns a FilePath corresponding to the directory containing the path
257*6777b538SAndroid Build Coastguard Worker   // named by this object, stripping away the file component.  If this object
258*6777b538SAndroid Build Coastguard Worker   // only contains one component, returns a FilePath identifying
259*6777b538SAndroid Build Coastguard Worker   // kCurrentDirectory.  If this object already refers to the root directory,
260*6777b538SAndroid Build Coastguard Worker   // returns a FilePath identifying the root directory. Please note that this
261*6777b538SAndroid Build Coastguard Worker   // doesn't resolve directory navigation, e.g. the result for "../a" is "..".
262*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath DirName() const;
263*6777b538SAndroid Build Coastguard Worker 
264*6777b538SAndroid Build Coastguard Worker   // Returns a FilePath corresponding to the last path component of this
265*6777b538SAndroid Build Coastguard Worker   // object, either a file or a directory.  If this object already refers to
266*6777b538SAndroid Build Coastguard Worker   // the root directory, returns a FilePath identifying the root directory;
267*6777b538SAndroid Build Coastguard Worker   // this is the only situation in which BaseName will return an absolute path.
268*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath BaseName() const;
269*6777b538SAndroid Build Coastguard Worker 
270*6777b538SAndroid Build Coastguard Worker   // Returns the extension of a file path.  This method works very similarly to
271*6777b538SAndroid Build Coastguard Worker   // FinalExtension(), except when the file path ends with a common
272*6777b538SAndroid Build Coastguard Worker   // double-extension.  For common double-extensions like ".tar.gz" and
273*6777b538SAndroid Build Coastguard Worker   // ".user.js", this method returns the combined extension.
274*6777b538SAndroid Build Coastguard Worker   //
275*6777b538SAndroid Build Coastguard Worker   // Common means that detecting double-extensions is based on a hard-coded
276*6777b538SAndroid Build Coastguard Worker   // allow-list (including but not limited to ".*.gz" and ".user.js") and isn't
277*6777b538SAndroid Build Coastguard Worker   // solely dependent on the number of dots.  Specifically, even if somebody
278*6777b538SAndroid Build Coastguard Worker   // invents a new Blah compression algorithm:
279*6777b538SAndroid Build Coastguard Worker   //   - calling this function with "foo.tar.bz2" will return ".tar.bz2", but
280*6777b538SAndroid Build Coastguard Worker   //   - calling this function with "foo.tar.blah" will return just ".blah"
281*6777b538SAndroid Build Coastguard Worker   //     until ".*.blah" is added to the hard-coded allow-list.
282*6777b538SAndroid Build Coastguard Worker   //
283*6777b538SAndroid Build Coastguard Worker   // That hard-coded allow-list is case-insensitive: ".GZ" and ".gz" are
284*6777b538SAndroid Build Coastguard Worker   // equivalent. However, the StringType returned is not canonicalized for
285*6777b538SAndroid Build Coastguard Worker   // case: "foo.TAR.bz2" input will produce ".TAR.bz2", not ".tar.bz2", and
286*6777b538SAndroid Build Coastguard Worker   // "bar.EXT", which is not a double-extension, will produce ".EXT".
287*6777b538SAndroid Build Coastguard Worker   //
288*6777b538SAndroid Build Coastguard Worker   // The following code should always work regardless of the value of path.
289*6777b538SAndroid Build Coastguard Worker   //   new_path = path.RemoveExtension().value().append(path.Extension());
290*6777b538SAndroid Build Coastguard Worker   //   ASSERT(new_path == path.value());
291*6777b538SAndroid Build Coastguard Worker   //
292*6777b538SAndroid Build Coastguard Worker   // NOTE: this is different from the original file_util implementation which
293*6777b538SAndroid Build Coastguard Worker   // returned the extension without a leading "." ("jpg" instead of ".jpg").
294*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] StringType Extension() const;
295*6777b538SAndroid Build Coastguard Worker 
296*6777b538SAndroid Build Coastguard Worker   // Returns the final extension of a file path, or an empty string if the file
297*6777b538SAndroid Build Coastguard Worker   // path has no extension.  In most cases, the final extension of a file path
298*6777b538SAndroid Build Coastguard Worker   // refers to the part of the file path from the last dot to the end (including
299*6777b538SAndroid Build Coastguard Worker   // the dot itself).  For example, this method applied to "/pics/jojo.jpg"
300*6777b538SAndroid Build Coastguard Worker   // and "/pics/jojo." returns ".jpg" and ".", respectively.  However, if the
301*6777b538SAndroid Build Coastguard Worker   // base name of the file path is either "." or "..", this method returns an
302*6777b538SAndroid Build Coastguard Worker   // empty string.
303*6777b538SAndroid Build Coastguard Worker   //
304*6777b538SAndroid Build Coastguard Worker   // TODO(davidben): Check all our extension-sensitive code to see if
305*6777b538SAndroid Build Coastguard Worker   // we can rename this to Extension() and the other to something like
306*6777b538SAndroid Build Coastguard Worker   // LongExtension(), defaulting to short extensions and leaving the
307*6777b538SAndroid Build Coastguard Worker   // long "extensions" to logic like base::GetUniquePathNumber().
308*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] StringType FinalExtension() const;
309*6777b538SAndroid Build Coastguard Worker 
310*6777b538SAndroid Build Coastguard Worker   // Returns "C:\pics\jojo" for path "C:\pics\jojo.jpg"
311*6777b538SAndroid Build Coastguard Worker   // NOTE: this is slightly different from the similar file_util implementation
312*6777b538SAndroid Build Coastguard Worker   // which returned simply 'jojo'.
313*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath RemoveExtension() const;
314*6777b538SAndroid Build Coastguard Worker 
315*6777b538SAndroid Build Coastguard Worker   // Removes the path's file extension, as in RemoveExtension(), but
316*6777b538SAndroid Build Coastguard Worker   // ignores double extensions.
317*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath RemoveFinalExtension() const;
318*6777b538SAndroid Build Coastguard Worker 
319*6777b538SAndroid Build Coastguard Worker   // Inserts |suffix| after the file name portion of |path| but before the
320*6777b538SAndroid Build Coastguard Worker   // extension.  Returns "" if BaseName() == "." or "..".
321*6777b538SAndroid Build Coastguard Worker   // Examples:
322*6777b538SAndroid Build Coastguard Worker   // path == "C:\pics\jojo.jpg" suffix == " (1)", returns "C:\pics\jojo (1).jpg"
323*6777b538SAndroid Build Coastguard Worker   // path == "jojo.jpg"         suffix == " (1)", returns "jojo (1).jpg"
324*6777b538SAndroid Build Coastguard Worker   // path == "C:\pics\jojo"     suffix == " (1)", returns "C:\pics\jojo (1)"
325*6777b538SAndroid Build Coastguard Worker   // path == "C:\pics.old\jojo" suffix == " (1)", returns "C:\pics.old\jojo (1)"
326*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath InsertBeforeExtension(StringPieceType suffix) const;
327*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath InsertBeforeExtensionASCII(StringPiece suffix) const;
328*6777b538SAndroid Build Coastguard Worker 
329*6777b538SAndroid Build Coastguard Worker   // Adds |extension| to |file_name|. Returns the current FilePath if
330*6777b538SAndroid Build Coastguard Worker   // |extension| is empty. Returns "" if BaseName() == "." or "..".
331*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath AddExtension(StringPieceType extension) const;
332*6777b538SAndroid Build Coastguard Worker 
333*6777b538SAndroid Build Coastguard Worker   // Like above, but takes the extension as an ASCII string. See AppendASCII for
334*6777b538SAndroid Build Coastguard Worker   // details on how this is handled.
335*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath AddExtensionASCII(StringPiece extension) const;
336*6777b538SAndroid Build Coastguard Worker 
337*6777b538SAndroid Build Coastguard Worker   // Replaces the extension of |file_name| with |extension|.  If |file_name|
338*6777b538SAndroid Build Coastguard Worker   // does not have an extension, then |extension| is added.  If |extension| is
339*6777b538SAndroid Build Coastguard Worker   // empty, then the extension is removed from |file_name|.
340*6777b538SAndroid Build Coastguard Worker   // Returns "" if BaseName() == "." or "..".
341*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath ReplaceExtension(StringPieceType extension) const;
342*6777b538SAndroid Build Coastguard Worker 
343*6777b538SAndroid Build Coastguard Worker   // Returns true if file path's Extension() matches `extension`. The test is
344*6777b538SAndroid Build Coastguard Worker   // case insensitive. Don't forget the leading period if appropriate.
345*6777b538SAndroid Build Coastguard Worker   bool MatchesExtension(StringPieceType extension) const;
346*6777b538SAndroid Build Coastguard Worker 
347*6777b538SAndroid Build Coastguard Worker   // Returns true if file path's FinalExtension() matches `extension`. The
348*6777b538SAndroid Build Coastguard Worker   // test is case insensitive. Don't forget the leading period if appropriate.
349*6777b538SAndroid Build Coastguard Worker   bool MatchesFinalExtension(StringPieceType extension) const;
350*6777b538SAndroid Build Coastguard Worker 
351*6777b538SAndroid Build Coastguard Worker   // Returns a FilePath by appending a separator and the supplied path
352*6777b538SAndroid Build Coastguard Worker   // component to this object's path.  Append takes care to avoid adding
353*6777b538SAndroid Build Coastguard Worker   // excessive separators if this object's path already ends with a separator.
354*6777b538SAndroid Build Coastguard Worker   // If this object's path is kCurrentDirectory ('.'), a new FilePath
355*6777b538SAndroid Build Coastguard Worker   // corresponding only to |component| is returned.  |component| must be a
356*6777b538SAndroid Build Coastguard Worker   // relative path; it is an error to pass an absolute path.
357*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath Append(StringPieceType component) const;
358*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath Append(const FilePath& component) const;
359*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath Append(const SafeBaseName& component) const;
360*6777b538SAndroid Build Coastguard Worker 
361*6777b538SAndroid Build Coastguard Worker   // Although Windows StringType is std::wstring, since the encoding it uses for
362*6777b538SAndroid Build Coastguard Worker   // paths is well defined, it can handle ASCII path components as well.
363*6777b538SAndroid Build Coastguard Worker   // Mac uses UTF8, and since ASCII is a subset of that, it works there as well.
364*6777b538SAndroid Build Coastguard Worker   // On Linux, although it can use any 8-bit encoding for paths, we assume that
365*6777b538SAndroid Build Coastguard Worker   // ASCII is a valid subset, regardless of the encoding, since many operating
366*6777b538SAndroid Build Coastguard Worker   // system paths will always be ASCII.
367*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath AppendASCII(StringPiece component) const;
368*6777b538SAndroid Build Coastguard Worker 
369*6777b538SAndroid Build Coastguard Worker   // Returns true if this FilePath contains an absolute path.  On Windows, an
370*6777b538SAndroid Build Coastguard Worker   // absolute path begins with either a drive letter specification followed by
371*6777b538SAndroid Build Coastguard Worker   // a separator character, or with two separator characters.  On POSIX
372*6777b538SAndroid Build Coastguard Worker   // platforms, an absolute path begins with a separator character.
373*6777b538SAndroid Build Coastguard Worker   bool IsAbsolute() const;
374*6777b538SAndroid Build Coastguard Worker 
375*6777b538SAndroid Build Coastguard Worker   // Returns true if this FilePath is a network path which starts with 2 path
376*6777b538SAndroid Build Coastguard Worker   // separators. See class documentation for 'Alternate root'.
377*6777b538SAndroid Build Coastguard Worker   bool IsNetwork() const;
378*6777b538SAndroid Build Coastguard Worker 
379*6777b538SAndroid Build Coastguard Worker   // Returns true if the patch ends with a path separator character.
380*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] bool EndsWithSeparator() const;
381*6777b538SAndroid Build Coastguard Worker 
382*6777b538SAndroid Build Coastguard Worker   // Returns a copy of this FilePath that ends with a trailing separator. If
383*6777b538SAndroid Build Coastguard Worker   // the input path is empty, an empty FilePath will be returned.
384*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath AsEndingWithSeparator() const;
385*6777b538SAndroid Build Coastguard Worker 
386*6777b538SAndroid Build Coastguard Worker   // Returns a copy of this FilePath that does not end with a trailing
387*6777b538SAndroid Build Coastguard Worker   // separator.
388*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath StripTrailingSeparators() const;
389*6777b538SAndroid Build Coastguard Worker 
390*6777b538SAndroid Build Coastguard Worker   // Returns true if this FilePath contains an attempt to reference a parent
391*6777b538SAndroid Build Coastguard Worker   // directory (e.g. has a path component that is "..").
392*6777b538SAndroid Build Coastguard Worker   bool ReferencesParent() const;
393*6777b538SAndroid Build Coastguard Worker 
394*6777b538SAndroid Build Coastguard Worker   // Return a Unicode human-readable version of this path.
395*6777b538SAndroid Build Coastguard Worker   // Warning: you can *not*, in general, go from a display name back to a real
396*6777b538SAndroid Build Coastguard Worker   // path.  Only use this when displaying paths to users, not just when you
397*6777b538SAndroid Build Coastguard Worker   // want to stuff a std::u16string into some other API.
398*6777b538SAndroid Build Coastguard Worker   std::u16string LossyDisplayName() const;
399*6777b538SAndroid Build Coastguard Worker 
400*6777b538SAndroid Build Coastguard Worker   // Return the path as ASCII, or the empty string if the path is not ASCII.
401*6777b538SAndroid Build Coastguard Worker   // This should only be used for cases where the FilePath is representing a
402*6777b538SAndroid Build Coastguard Worker   // known-ASCII filename.
403*6777b538SAndroid Build Coastguard Worker   std::string MaybeAsASCII() const;
404*6777b538SAndroid Build Coastguard Worker 
405*6777b538SAndroid Build Coastguard Worker   // Return the path as UTF-8.
406*6777b538SAndroid Build Coastguard Worker   //
407*6777b538SAndroid Build Coastguard Worker   // This function is *unsafe* as there is no way to tell what encoding is
408*6777b538SAndroid Build Coastguard Worker   // used in file names on POSIX systems other than Mac and Chrome OS,
409*6777b538SAndroid Build Coastguard Worker   // although UTF-8 is practically used everywhere these days. To mitigate
410*6777b538SAndroid Build Coastguard Worker   // the encoding issue, this function internally calls
411*6777b538SAndroid Build Coastguard Worker   // SysNativeMBToWide() on POSIX systems other than Mac and Chrome OS,
412*6777b538SAndroid Build Coastguard Worker   // per assumption that the current locale's encoding is used in file
413*6777b538SAndroid Build Coastguard Worker   // names, but this isn't a perfect solution.
414*6777b538SAndroid Build Coastguard Worker   //
415*6777b538SAndroid Build Coastguard Worker   // Once it becomes safe to to stop caring about non-UTF-8 file names,
416*6777b538SAndroid Build Coastguard Worker   // the SysNativeMBToWide() hack will be removed from the code, along
417*6777b538SAndroid Build Coastguard Worker   // with "Unsafe" in the function name.
418*6777b538SAndroid Build Coastguard Worker   std::string AsUTF8Unsafe() const;
419*6777b538SAndroid Build Coastguard Worker 
420*6777b538SAndroid Build Coastguard Worker   // Similar to AsUTF8Unsafe, but returns UTF-16 instead.
421*6777b538SAndroid Build Coastguard Worker   std::u16string AsUTF16Unsafe() const;
422*6777b538SAndroid Build Coastguard Worker 
423*6777b538SAndroid Build Coastguard Worker   // Returns a FilePath object from a path name in ASCII.
424*6777b538SAndroid Build Coastguard Worker   static FilePath FromASCII(StringPiece ascii);
425*6777b538SAndroid Build Coastguard Worker 
426*6777b538SAndroid Build Coastguard Worker   // Returns a FilePath object from a path name in UTF-8. This function
427*6777b538SAndroid Build Coastguard Worker   // should only be used for cases where you are sure that the input
428*6777b538SAndroid Build Coastguard Worker   // string is UTF-8.
429*6777b538SAndroid Build Coastguard Worker   //
430*6777b538SAndroid Build Coastguard Worker   // Like AsUTF8Unsafe(), this function is unsafe. This function
431*6777b538SAndroid Build Coastguard Worker   // internally calls SysWideToNativeMB() on POSIX systems other than Mac
432*6777b538SAndroid Build Coastguard Worker   // and Chrome OS, to mitigate the encoding issue. See the comment at
433*6777b538SAndroid Build Coastguard Worker   // AsUTF8Unsafe() for details.
434*6777b538SAndroid Build Coastguard Worker   static FilePath FromUTF8Unsafe(StringPiece utf8);
435*6777b538SAndroid Build Coastguard Worker 
436*6777b538SAndroid Build Coastguard Worker   // Similar to FromUTF8Unsafe, but accepts UTF-16 instead.
437*6777b538SAndroid Build Coastguard Worker   static FilePath FromUTF16Unsafe(StringPiece16 utf16);
438*6777b538SAndroid Build Coastguard Worker 
439*6777b538SAndroid Build Coastguard Worker   void WriteToPickle(Pickle* pickle) const;
440*6777b538SAndroid Build Coastguard Worker   bool ReadFromPickle(PickleIterator* iter);
441*6777b538SAndroid Build Coastguard Worker 
442*6777b538SAndroid Build Coastguard Worker   // Normalize all path separators to backslash on Windows
443*6777b538SAndroid Build Coastguard Worker   // (if FILE_PATH_USES_WIN_SEPARATORS is true), or do nothing on POSIX systems.
444*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath NormalizePathSeparators() const;
445*6777b538SAndroid Build Coastguard Worker 
446*6777b538SAndroid Build Coastguard Worker   // Normalize all path separattors to given type on Windows
447*6777b538SAndroid Build Coastguard Worker   // (if FILE_PATH_USES_WIN_SEPARATORS is true), or do nothing on POSIX systems.
448*6777b538SAndroid Build Coastguard Worker   [[nodiscard]] FilePath NormalizePathSeparatorsTo(CharType separator) const;
449*6777b538SAndroid Build Coastguard Worker 
450*6777b538SAndroid Build Coastguard Worker   // Compare two strings in the same way the file system does.
451*6777b538SAndroid Build Coastguard Worker   // Note that these always ignore case, even on file systems that are case-
452*6777b538SAndroid Build Coastguard Worker   // sensitive. If case-sensitive comparison is ever needed, add corresponding
453*6777b538SAndroid Build Coastguard Worker   // methods here.
454*6777b538SAndroid Build Coastguard Worker   // The methods are written as a static method so that they can also be used
455*6777b538SAndroid Build Coastguard Worker   // on parts of a file path, e.g., just the extension.
456*6777b538SAndroid Build Coastguard Worker   // CompareIgnoreCase() returns -1, 0 or 1 for less-than, equal-to and
457*6777b538SAndroid Build Coastguard Worker   // greater-than respectively.
458*6777b538SAndroid Build Coastguard Worker   static int CompareIgnoreCase(StringPieceType string1,
459*6777b538SAndroid Build Coastguard Worker                                StringPieceType string2);
CompareEqualIgnoreCase(StringPieceType string1,StringPieceType string2)460*6777b538SAndroid Build Coastguard Worker   static bool CompareEqualIgnoreCase(StringPieceType string1,
461*6777b538SAndroid Build Coastguard Worker                                      StringPieceType string2) {
462*6777b538SAndroid Build Coastguard Worker     return CompareIgnoreCase(string1, string2) == 0;
463*6777b538SAndroid Build Coastguard Worker   }
CompareLessIgnoreCase(StringPieceType string1,StringPieceType string2)464*6777b538SAndroid Build Coastguard Worker   static bool CompareLessIgnoreCase(StringPieceType string1,
465*6777b538SAndroid Build Coastguard Worker                                     StringPieceType string2) {
466*6777b538SAndroid Build Coastguard Worker     return CompareIgnoreCase(string1, string2) < 0;
467*6777b538SAndroid Build Coastguard Worker   }
468*6777b538SAndroid Build Coastguard Worker 
469*6777b538SAndroid Build Coastguard Worker   // Serialise this object into a trace.
470*6777b538SAndroid Build Coastguard Worker   void WriteIntoTrace(perfetto::TracedValue context) const;
471*6777b538SAndroid Build Coastguard Worker 
472*6777b538SAndroid Build Coastguard Worker #if BUILDFLAG(IS_APPLE)
473*6777b538SAndroid Build Coastguard Worker   // Returns the string in the special canonical decomposed form as defined for
474*6777b538SAndroid Build Coastguard Worker   // HFS, which is close to, but not quite, decomposition form D. See
475*6777b538SAndroid Build Coastguard Worker   // http://developer.apple.com/mac/library/technotes/tn/tn1150.html#UnicodeSubtleties
476*6777b538SAndroid Build Coastguard Worker   // for further comments.
477*6777b538SAndroid Build Coastguard Worker   // Returns the epmty string if the conversion failed.
478*6777b538SAndroid Build Coastguard Worker   static StringType GetHFSDecomposedForm(StringPieceType string);
479*6777b538SAndroid Build Coastguard Worker 
480*6777b538SAndroid Build Coastguard Worker   // Special UTF-8 version of FastUnicodeCompare. Cf:
481*6777b538SAndroid Build Coastguard Worker   // http://developer.apple.com/mac/library/technotes/tn/tn1150.html#StringComparisonAlgorithm
482*6777b538SAndroid Build Coastguard Worker   // IMPORTANT: The input strings must be in the special HFS decomposed form!
483*6777b538SAndroid Build Coastguard Worker   // (cf. above GetHFSDecomposedForm method)
484*6777b538SAndroid Build Coastguard Worker   static int HFSFastUnicodeCompare(StringPieceType string1,
485*6777b538SAndroid Build Coastguard Worker                                    StringPieceType string2);
486*6777b538SAndroid Build Coastguard Worker #endif
487*6777b538SAndroid Build Coastguard Worker 
488*6777b538SAndroid Build Coastguard Worker #if BUILDFLAG(IS_ANDROID)
489*6777b538SAndroid Build Coastguard Worker   // On android, file selection dialog can return a file with content uri
490*6777b538SAndroid Build Coastguard Worker   // scheme(starting with content://). Content uri needs to be opened with
491*6777b538SAndroid Build Coastguard Worker   // ContentResolver to guarantee that the app has appropriate permissions
492*6777b538SAndroid Build Coastguard Worker   // to access it.
493*6777b538SAndroid Build Coastguard Worker   // Returns true if the path is a content uri, or false otherwise.
494*6777b538SAndroid Build Coastguard Worker   bool IsContentUri() const;
495*6777b538SAndroid Build Coastguard Worker #endif
496*6777b538SAndroid Build Coastguard Worker 
497*6777b538SAndroid Build Coastguard Worker   // NOTE: When adding a new public method, consider adding it to
498*6777b538SAndroid Build Coastguard Worker   // file_path_fuzzer.cc as well.
499*6777b538SAndroid Build Coastguard Worker 
500*6777b538SAndroid Build Coastguard Worker  private:
501*6777b538SAndroid Build Coastguard Worker   // Remove trailing separators from this object.  If the path is absolute, it
502*6777b538SAndroid Build Coastguard Worker   // will never be stripped any more than to refer to the absolute root
503*6777b538SAndroid Build Coastguard Worker   // directory, so "////" will become "/", not "".  A leading pair of
504*6777b538SAndroid Build Coastguard Worker   // separators is never stripped, to support alternate roots.  This is used to
505*6777b538SAndroid Build Coastguard Worker   // support UNC paths on Windows.
506*6777b538SAndroid Build Coastguard Worker   void StripTrailingSeparatorsInternal();
507*6777b538SAndroid Build Coastguard Worker 
508*6777b538SAndroid Build Coastguard Worker   StringType path_;
509*6777b538SAndroid Build Coastguard Worker };
510*6777b538SAndroid Build Coastguard Worker 
511*6777b538SAndroid Build Coastguard Worker BASE_EXPORT std::ostream& operator<<(std::ostream& out,
512*6777b538SAndroid Build Coastguard Worker                                      const FilePath& file_path);
513*6777b538SAndroid Build Coastguard Worker 
514*6777b538SAndroid Build Coastguard Worker }  // namespace base
515*6777b538SAndroid Build Coastguard Worker 
516*6777b538SAndroid Build Coastguard Worker namespace std {
517*6777b538SAndroid Build Coastguard Worker 
518*6777b538SAndroid Build Coastguard Worker template <>
519*6777b538SAndroid Build Coastguard Worker struct hash<base::FilePath> {
520*6777b538SAndroid Build Coastguard Worker   typedef base::FilePath argument_type;
521*6777b538SAndroid Build Coastguard Worker   typedef std::size_t result_type;
522*6777b538SAndroid Build Coastguard Worker   result_type operator()(argument_type const& f) const {
523*6777b538SAndroid Build Coastguard Worker     return hash<base::FilePath::StringType>()(f.value());
524*6777b538SAndroid Build Coastguard Worker   }
525*6777b538SAndroid Build Coastguard Worker };
526*6777b538SAndroid Build Coastguard Worker 
527*6777b538SAndroid Build Coastguard Worker }  // namespace std
528*6777b538SAndroid Build Coastguard Worker 
529*6777b538SAndroid Build Coastguard Worker #endif  // BASE_FILES_FILE_PATH_H_
530